1. Field of the Invention
The present invention relates to a substrate transfer apparatus and a substrate transfer method to transfer a substrate stopped at a first position toward a second position and to stop the substrate at the second position, and a surface mounter that mounts components on the substrate positioned at the second position by the substrate transfer apparatus.
2. Description of the Background Art
With a substrate processing system that mounts electronic components on a substrate, substrate processing apparatuses such as a printer, a print inspector, a surface mounter, a mount inspection apparatus, and the like are installed side by side along a transfer path. The respective substrate processing apparatuses perform desired processes according to a processing program on a substrate transferred along a substrate transfer path. As for a surface mounter, for example, a substrate transfer mechanism transfers a substrate to a predetermined target position of the surface mounter. The substrate transfer mechanism then stops the substrate at a predetermined target position. The transferred substrate is then subjected to a component mounting where electronic components, such as an IC (Integrated Circuit) supplied from a component supplying section such as a tape feeder, are mounted onto the substrate. Upon completing the component mounting operation, the substrate is shipped from the target position. Such a series of substrate processing operations (substrate transfer, component mounting, and substrate shipping) is repetitively performed.
In order to perform the substrate processing operations described above on substrates of the same type in an efficient manner, the substrates must be transferred accurately to a target position. Also the substrates must be positioned accurately at the target position. To meet with the demand, a conventional apparatus, for example described in JP Patent Publication No. 2009-27202, obtains an amount of misregistration amount of an actual substrate stop position with respect to a target position of a substrate in order to execute a feedback control. The substrate transfer parameters are then modified in accordance with the misregistration amount. The apparatus transfers a next substrate using the modified substrate transfer parameters. Relying upon the aforementioned feedback control, the conventional apparatus tried to achieve appropriate substrate transfer.
According to the apparatus described in JP Patent Publication No. 2009-27202, substrate processing operations must be performed on at least one substrate to obtain an amount of misregistration in order to optimize substrate transfer. Therefore, it is still difficult to perform accurate operation with respect to a first substrate in transferring to the target position. In addition, unexpected factors may arise during substrate transfer such as an occurrence of belt deterioration or substrate slippage while a substrate is being transferred by a belt. However, the apparatus described in JP Patent Publication No. 2009-27202 is unable to accommodate such unexpected factors. Hence, it is difficult to transfer a substrate to a target position and positioning the substrate at the target position in a stable manner.